Android 如何将Canvas上绘制的内容保存成本地图片

效果如下图所示

保存在sd卡上的文件为

手机上显示效果为：

1》》在Manifest文件中增加相应权限

    <!-- 在SDCard中创建与删除文件权限 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <!-- 往SDCard写入数据权限 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

例如我的Manifest文件代码如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.demo.picturetest"
    android:versionCode="1"
    android:versionName="1.0" >

    <!-- 在SDCard中创建与删除文件权限 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <!-- 往SDCard写入数据权限 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

2》》详细代码如下

package com.demo.picturetest;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.widget.ImageView;

public class MainActivity extends Activity {
	private Bitmap mBitmap;
	// 画布
	private Canvas mCanvas;
	// 画笔－－画图片
	private Paint mPicturePaint = new Paint();
	// 画笔－－写字
	private Paint mTextPaint = new Paint();
	// 画笔－－写运动数据
	private Paint mDataPaint = new Paint();

	private ImageView mImageView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		drawBitmap();
		init();
		// 展示
		mImageView.setImageBitmap(mBitmap);

	}

	private void init() {
		mImageView = (ImageView) findViewById(R.id.mImageView);
	}

	/**
	 * 根据图片和文字生成图片
	 * */
	private void drawBitmap() {

		Bitmap bm_bg = BitmapFactory.decodeResource(getResources(),
				R.drawable.dashboard_bg);
		// 得到图片的宽、高
		int width_bg = bm_bg.getWidth();
		int height_bg = bm_bg.getHeight();

		// 创建一个你需要尺寸的Bitmap
		mBitmap = Bitmap.createBitmap(width_bg, height_bg, Config.ARGB_8888);
		// 用这个Bitmap生成一个Canvas,然后canvas就会把内容绘制到上面这个bitmap中
		mCanvas = new Canvas(mBitmap);

		// 绘制背景图片
		mCanvas.drawBitmap(bm_bg, 0.0f, 0.0f, mPicturePaint);
		// 绘制图片
		Bitmap bm_head = BitmapFactory.decodeResource(getResources(),
				R.drawable.share_head_img);

		// 得到图片的宽、高
		int width_head = bm_head.getWidth();
		int height_head = bm_head.getHeight();
		// 绘制图片－－保证其在水平方向居中
		mCanvas.drawBitmap(bm_head, (width_bg - width_head) / 2, 0.0f,
				mPicturePaint);

		// 绘制文字
		mTextPaint.setColor(Color.WHITE);// 白色画笔
		mTextPaint.setTextSize(80.0f);// 设置字体大小

		// 绘制文字
		mDataPaint.setColor(Color.RED);// 红色画笔
		mDataPaint.setTextSize(120.0f);// 设置字体大小

		String distanceTextString = "运动距离：";
		String distanceDataString = String.valueOf(888);
		String distanceScalString = "米";

		float distanceTextString_width = mTextPaint.measureText(
				distanceTextString, 0, distanceTextString.length());

		float distanceDataString_width = mDataPaint.measureText(
				distanceDataString, 0, distanceDataString.length());
		float distanceScalString_width = mTextPaint.measureText(
				distanceScalString, 0, distanceScalString.length());
		float x = (width_bg - distanceTextString_width
				- distanceDataString_width - distanceScalString_width) / 2;

		mCanvas.drawText(distanceTextString, x, height_head, mTextPaint);// 绘制文字
		mCanvas.drawText(distanceDataString, x + distanceTextString_width,
				height_head, mDataPaint);// 绘制文字

		mCanvas.drawText(distanceScalString, x + distanceTextString_width
				+ distanceDataString_width, height_head, mTextPaint);// 绘制文字

		// 保存绘图为本地图片
		mCanvas.save(Canvas.ALL_SAVE_FLAG);
		mCanvas.restore();

		File file = new File(Environment.getExternalStorageDirectory()
				.getPath() + "/share_pic.png");// 保存到sdcard根目录下，文件名为share_pic.png
		Log.i("CXC", Environment.getExternalStorageDirectory().getPath());
		FileOutputStream fos = null;
		try {
			fos = new FileOutputStream(file);
			mBitmap.compress(Bitmap.CompressFormat.PNG, 50, fos);

		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		try {
			fos.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}
}